Sudden infant death syndrome (SIDS) refers to the unexpected, unexplained death of a child less than one year of age. The occurrence of SIDS is rare during the first month of life, peaks at 2-3 months of age, then gradually decreases.

Causes

Experts do not know why some infants suddenly die. Research continues in hope of finding a preventable cause. Many theories exist and it is likely that research will reveal that among babies who die of SIDS there are several different but important causes. Some suggested causes include:

• Abnormalities in a section of the brain that controls breathing during sleep and waking

• Abnormalities in the control of heart rhythm

• Abnormalities in the way that some babies metabolize substances called fatty acid

• Further theories suggest that the following could play a role

• • Lack of oxygen and nutrients during development or after birth

• • Taking in too much carbon dioxide or re-breathing exhaled air

• • Overheating

• • An infection that interferes with breathing

• • Excess proteins produced by the immune system

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition.

• Infant's age: less than 4 months old

• Low birth weight

• History of SIDS death in a sibling

• Previous incident of severe apnea, requiring resuscitation

• Sleeping on the stomach or side rather than back

• Other risk factors are more general and include:

• • Mother's age: younger than 20 during first pregnancy

• • Poverty, especially in black and Native American families

• • Sex: male

• • Smoking during pregnancy or in a house where the baby is sleeping

• • Opiate or cocaine use during pregnancy

• • History of anemia or a urinary tract infection while pregnant

• • No or late prenatal care

• • Premature birth

• • Recent infection and/or fever

• • Cold weather in late fall or winter

• • Overheating

Symptoms

A baby that dies of SIDS typically appears healthy. He or she may have had a cold or gastrointestinal infection in the two weeks prior to death. There usually are no warning signs that a baby is about to die of SIDS.

Diagnosis

All possible illnesses and causes of death must be ruled out before a diagnosis of SIDS is made. A complete investigation will take place including:

• Autopsy

• Assessment of the death scene

• Review of the baby's and family's medical histories

Treatment

Emergency medical personnel should be called as soon as the infant is discovered not breathing. Infant, not adult, cardiopulmonary resuscitation (CPR) should be started immediately (both types of CPR are taught at Basic Life Support courses which are widely available in the U.S.). Seek immediate medical medical care even if the baby starts breathing again. The cause of the incident should be fully evaluated. Families may need grief counseling after the death. Some parents find support groups helpful.

Prevention

There is no way to predict which infants will die of SIDS. Several actions may help you lower the risk of SIDS:

During pregnancy:

• Get prenatal care early and regularly.

• Do not smoke or use drugs while pregnant.

After birth:

• Put the baby down to sleep on his or her back. Do not allow a young baby to sleep on his or her stomach or side. Adoption of “back to sleep” practices has significantly reduced the occurrence of SIDS in many countries. Ask your doctor for more information about positioning your baby for sleep.

• Other factors that may help reduce SIDS risk include:

• • Provide a firm crib mattress.

• • Do not place blankets, a comforter, pillow or sheepskin under the baby.

• • Do not let the baby sleep on a waterbed.

• • Remove soft, stuffed toys from the bed.

• • Keep the baby's room at a comfortable temperature (68-72°F).

• • Do not overdress the baby.

• • Allow pacifier use during nap time and bedtime.

• • Do not cover the baby's head or face.

• • Do not smoke in the house, or quit entirely.

• • Take the baby for regular medical care.

• • Have your child immunized at the recommended times.

• • Learn infant CPR.

• • Allow the infant to sleep in their crib in the same room you sleep in (but do not let them sleep in the same bed)

• • Make sure anyone else caring for your child is also aware of these recommendations, especially that the baby should be placed on his or her back for sleeping.

• If you have had previous children die of SIDS, your doctor may suggest the use of an “apnea monitor” to record the child’s breathing.

RESOURCES:

National SIDS/Infant Death Resource Center
http://www.sidscenter.org

Sudden Infant Death Syndrome Alliance
http://www.sidsalliance.org/

References:

American Academy of Pediatrics SIDS Task Force. The changing concept of Sudden Infant Death Syndrome: Diagnostic coding shifts, controversies regarding the sleeping environment, and new variables to consider in reducing risk. Pediatrics. 2005;116(5):1245-1255.

Current Pediatrics, 17th edition. McGraw-Hill, 2005.

Galland BC et al. Prone versus supine sleep position: a review of the physiological studies in SIDS research. J Paediatr Child Health. 2002;38(4):332-338.

National Institute of Child Health and Human Development. Avaulable at: http://www.nichd.nih.gov.

Nelson Textbook of Pediatrics, 16th Edition. W.B. Saunders, 2000.

Sudden Infant Death Syndrome Alliance. Available at: http://www.sidsalliance.org/.